K.T. McFarland, Trump's former deputy national security adviser, give a thumbs up to members of the media as she arrives at Trump Tower in New York, Tuesday, Jan. 3, 2017.

An email may have undermined a Trump administration associate who told Congress she knew nothing about a meeting between her boss and a Russian ambassador, according to a report.

K.T. McFarland, President Trump’s former deputy national security adviser, told lawmakers over the summer that she did not discuss or know anything about meetings between Sergey Kislyak, Moscow’s former ambassador to the U.S., and Michael Flynn, the fired White House aide who pleaded guilty to lying to the FBI about his conversations with a Russian diplomat.

But a Dec. 29 email from McFarland, then a member of Trump’s transition team, mentioned that Flynn would be talking to the Russian ambassador that evening, according to The New York Times.

The topic, according to the email, was about Obama administration sanctions against Russia for interfering in the 2016 elections.

McFarland served as deputy national security adviser until May, when she was nominated to be the ambassador to Singapore, an appointment that requires Senate confirmation.

As part of the confirmation process, McFarland was asked in writing a question about Flynn.

Michael Flynn stands with K.T. McFarland before speaking during the daily news briefing at the White House, in Washington, Wednesday, Feb. 1, 2017.

(Carolyn Kaster/AP)

“Did you ever discuss any of General Flynn’s contacts with Russian Ambassador Sergey Kislyak directly with General Flynn?” asked Sen. Cory Booker (D-N.J.), a member of the Senate Foreign Relations Committee

“I am not aware of any of the issues or events as described above,” McFarland replied.

The conflicting messages are bound to cause more headaches for the Trump administration as it defends itself against charges of collusion.

“Recent developments suggest that Ms. McFarland gave false testimony to the United States Senate on a matter as significant as communications between the Russian government and the Trump transition team,” Booker said in a statement to the Times.

“If this is the case, this is an alarming development, and another example of a pattern of deception on the part of Trump’s closest associates regarding their connections and communications to Russian government officials.”